Benji Marshall says he is keen to show he can again be a force in the NRL after signing a two-and-half year NRL deal with St George Illawarra.

The Dragons beat Cronulla to secure the signature of the former Wests Tigers superstar, after he severed ties with Super Rugby's Auckland Blues on Easter Monday after failing to successfully convert to the 15-man code.

Marshall's form was poor in his final year with the Tigers last season, and at one stage he was benched by coach Mick Potter. Marshall admitted he became lazy at the Tigers and was keen to turn that around.

"I have a point to prove. Not to everyone else, but to myself. I left on a low. My form was terrible," Marshall said at a press conference to trumpet his signing. "From my point of view I am ready to go. I feel like the new kid at school again and I think that will bring the best out of me.

"This move to the Dragons gets me out of my comfort zone. Do I think I am past my best now? No. Will it take time to get back? Yes. But I have the desire to get back to my best. I'm just pretty happy to be back in the NRL.

"It is a challenge, obviously there is going to be a lot of pressure on my performance. If that takes two weeks, three weeks, if I have to play reserve grade I'm happy to do that.”

Dragons coach Steve Price said Marshall would be a dynamic acquisition. "Benji is a quality player who I believe will bring that real x-factor, especially in our attack," Price said. "I have met with him a couple of times, he is a very proud man who wasn't happy with how his rugby league career ended and is really determined to make the most of his second chance in rugby league."

The Dragons are banking on Marshall to form a potent halves combination with Gareth Widdop as they attempt to reinvigorate themselves as premiership contenders. Widdop has been a revelation for the Dragons this season after his offseason move from Melbourne but he has struggled to find a regular halves partner with Michael Witt, Sam Williams and Adam Quinlan all used at half-back.

The joint venture started the season well, winning their opening three matches. But since then they have won just one of the next five.

Marshall could make his Dragons debut as soon as their round 10 clash with Parramatta at Pirtek Stadium on Saturday week. He will face his former club in round 20 at ANZ Stadium.

On Tuesday England pivot Widdop said Marshall would be a good signing for the joint venture. "As a young fellow, I played with some great players down at Melbourne so, to play with Benji - another great player - would be great too," Widdop said.

"Everyone knows what he has done for rugby league. He was a great player before he left for rugby union. Everyone watches footy to watch people like Benji and, to have him back, I'm sure it is going to attract a lot more attention which is great for rugby league."